U.S. patent number 9,575,283 [Application Number 14/884,349] was granted by the patent office on 2017-02-21 for voice coil motor.
This patent grant is currently assigned to LG INNOTEK CO., LTD.. The grantee listed for this patent is LG INNOTEK CO., LTD.. Invention is credited to Taemin Ha, Taejin Jung, Seungki Kim, Seongmin Lee, Sangjun Min, Sangok Park, Kyoungho Yoo.
United States Patent |
9,575,283 |
Lee , et al. |
February 21, 2017 |
Voice coil motor
Abstract
A VCM (voice coil motor) is disclosed, the VCM including: a
rotor including a lens-accommodating, both ends opened cylindrical
bobbin and a coil block including a coil wound on a periphery of
the bobbin; a stator including a cylindrical yoke formed with a
lens-exposing opening, a plurality of magnets disposed inside the
yoke and opposite to the coil block, and a housing disposed inside
the yoke to fix the plurality of magnets; and an elastic member
elastically supporting the bobbin.
Inventors: |
Lee; Seongmin (Seoul,
KR), Park; Sangok (Seoul, KR), Min;
Sangjun (Seoul, KR), Yoo; Kyoungho (Seoul,
KR), Jung; Taejin (Seoul, KR), Ha;
Taemin (Seoul, KR), Kim; Seungki (Seoul,
KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
LG INNOTEK CO., LTD. |
Seoul |
N/A |
KR |
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Assignee: |
LG INNOTEK CO., LTD. (Seoul,
KR)
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Family
ID: |
45526010 |
Appl.
No.: |
14/884,349 |
Filed: |
October 15, 2015 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20160033736 A1 |
Feb 4, 2016 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14457984 |
Aug 12, 2014 |
9190891 |
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13193706 |
Jul 29, 2011 |
8836177 |
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Foreign Application Priority Data
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Jul 30, 2010 [KR] |
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10-2010-0074002 |
Sep 8, 2010 [KR] |
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10-2010-0087943 |
Nov 18, 2010 [KR] |
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10-2010-0115163 |
Dec 1, 2010 [KR] |
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10-2010-0121320 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04N
5/2252 (20130101); H04N 5/44 (20130101); H02K
41/0356 (20130101); H02K 5/04 (20130101); H04N
5/2254 (20130101); G02B 7/023 (20130101); G02B
7/04 (20130101); H02K 41/035 (20130101) |
Current International
Class: |
G02B
7/02 (20060101); H02K 41/035 (20060101); H02K
5/04 (20060101); H04N 5/225 (20060101) |
Field of
Search: |
;310/12.16 ;359/824 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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201018387 |
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Feb 2008 |
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CN |
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201096947 |
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Aug 2008 |
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CN |
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101546093 |
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Sep 2009 |
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CN |
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2006074990 |
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Mar 2006 |
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JP |
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2006079072 |
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Mar 2006 |
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JP |
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2010160435 |
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Jul 2010 |
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JP |
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20070043567 |
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Apr 2007 |
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KR |
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20090032905 |
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Apr 2009 |
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KR |
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Other References
Office Action dated Dec. 15, 2014 in Chinese Application No.
201110218910.3. cited by applicant .
Office Action dated Aug. 12, 2016 in Korean Application No.
1020100074002. cited by applicant .
Office Action dated Sep. 29, 2016 in Korean Application No.
1020100087943. cited by applicant .
Office Action dated Dec. 5, 2016 in Korean Application No.
1020100115163. cited by applicant .
Office Action dated Dec. 9, 2016 in Korean Application No.
1020100121320. cited by applicant.
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Primary Examiner: Mok; Alex W
Attorney, Agent or Firm: Saliwanchik, Lloyd &
Eisenschenk
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. Ser. No. 14/457,984,
filed Aug. 12, 2014, which is a continuation of U.S. Ser. No.
13/193,706, filed Jul. 29, 2011, which claims the benefit under 35
U.S.C. .sctn.119 of Korean Application Nos. 10-2010-0074002, filed
Jul. 30, 2010; 10-2010-0087943, filed Sep. 8, 2010;
10-2010-0115163, filed Nov. 18, 2010; and 10-2010-0121320, filed
Dec. 1, 2010, all of which are hereby incorporated by reference in
their entirety.
Claims
The invention claimed is:
1. A VCM (voice coil motor) comprising: a housing comprising an
upper plate and a lateral plate, wherein an accommodation hole is
formed at the lateral plate of the housing; a bobbin disposed
inside the housing; a magnet disposed at the accommodation hole; a
coil block disposed on the bobbin and facing the magnet; a first
elastic member coupled with a lower portion of the bobbin and a
lower portion of the housing; a second elastic member coupled with
an upper portion of the bobbin and an upper portion of the housing;
a disengagement prevention unit inhibiting the magnet from being
disengaged from the housing in a direction towards the coil block;
and a stroke lug protruded from the upper plate of the housing to
provide a stroke space of the bobbin.
2. The VCM of claim 1, wherein the lateral plate extends from the
upper plate, and wherein the disengagement prevention unit is
protruded from the lateral plate to both-two edges of the magnet in
order to support each of said two edges of the magnet.
3. The VCM of claim 2, wherein the disengagement prevention unit is
brought into contact with a front surface of the magnet facing the
coil block.
4. The VCM of claim 2, wherein the disengagement prevention unit is
formed in a direction parallel with the upper plate.
5. The VCM of claim 2, wherein the disengagement prevention unit is
formed in a direction parallel with an optical axis.
6. The VCM of claim 2, wherein the disengagement prevention unit
includes a first disengagement prevention unit formed in a
direction parallel with the upper plate and a second disengagement
prevention unit formed in a direction parallel with an optical
axis.
7. The VCM of claim 2, wherein the disengagement prevention unit is
extended from an inner lateral surface of the lateral plate facing
the coil block to an interior of the accommodation hole, and
thickness of the magnet is same as that of the lateral plate.
8. The VCM of claim 2, wherein the disengagement prevention unit is
protruded from an accommodation surface formed by the accommodation
hole with a thickness thinner than that of the lateral plate, and
the magnet is formed with a thickness of the lateral plate minus
the thickness of the disengagement prevention unit.
9. The VCM of claim 2, wherein the disengagement prevention unit is
protruded from an accommodation surface formed by the accommodation
hole with a thickness thinner than that of the lateral plate, the
magnet contacted by the disengagement prevention unit is formed
with an accommodation groove accommodating the disengagement
prevention unit, and the thickness of the magnet accommodated into
the accommodation groove is same as that of the lateral plate.
10. The VCM of claim 1, wherein the magnet includes any one of a
two-pole flat magnet or a four-pole flat magnet.
11. The VCM of claim 1, wherein the magnet is formed by stacking
two magnets.
12. The VCM of claim 1, wherein the first elastic member comprises
a first plate spring and a second plate spring physically separated
from the first plate spring, and wherein the coil block is
electrically connected with the first plate spring and the second
plate spring.
13. The VCM of claim 12, further comprising: a cover can covering
the housing and coupled with a base disposed under the housing,
wherein the cover can comprises a cover can upper plate covering
the upper plate of the housing and contacted with the stroke lug,
and a cover can lateral plate extended from an edge of the cover
can upper plate to cover the lateral plate of the housing and to be
coupled to the base.
14. The VCM of claim 13, wherein the cover can upper plate and the
cover can lateral plate include metal plates, and the cover can
lateral plate is brought into contact with a rear surface of the
magnet opposite to a front surface of the magnet facing the coil
block.
15. The VCM of claim 1, wherein the stroke lug is formed at four
corners of the upper plate of the housing, and is formed in a pair
with each of the pair being distanced from the other, and wherein
the stroke lugs of the pair of stroke lugs take a mutually
symmetrical shape.
16. The VCM of claim 1, wherein the stroke lug is coupled to the
second elastic member.
17. The VCM of claim 1, wherein the second elastic member comprises
a hole having a shape corresponding with a portion of a shape of
the stroke lug, and wherein the hole of the second elastic member
is coupled with the stroke lug.
18. A VCM (voice coil motor) comprising: a housing comprising an
accommodation hole; a bobbin disposed at an inner side of the
housing; a magnet disposed at the accommodation hole; a coil block
disposed on the bobbin and facing the magnet; a first elastic
member coupled with a bottom surface of the bobbin and a bottom
surface of the housing; a second elastic member coupled with an
upper surface of the bobbin and an upper surface of the housing; a
disengagement prevention unit inhibiting the magnet from being
disengaged from the housing in a direction towards the coil block;
and a stroke lug protruded from an upper plate of the housing to
provide a stroke space of the bobbin, and to be coupled to the
second elastic member.
19. A camera module comprising: a circuit substrate; an image
sensor coupled with the circuit substrate; a housing disposed over
the circuit substrate and comprising an upper plate and a lateral
plate, wherein an accommodation hole is formed at the lateral plate
of the housing; a bobbin disposed inside the housing; a magnet
disposed at the accommodation hole; a coil block disposed on the
bobbin and facing the magnet; a first elastic member coupled with a
lower portion of the bobbin and a lower portion of the housing; a
second elastic member coupled with an upper portion of the bobbin
and an upper portion of the housing; a disengagement prevention
unit inhibiting the magnet from being disengaged from the housing
in a direction towards the coil block; and a stroke lug protruded
from the upper plate of the housing to provide a stroke space of
the bobbin.
20. A mobile phone comprising the camera module of claim 19.
Description
BACKGROUND OF THE DISCLOSURE
Field of the Disclosure
The present disclosure relates to a voice coil motor (VCM).
Discussion of the Related Art
Recently, a mobile phone mounted with a super-small high resolution
digital camera has been developed. The super-small digital camera
mounted on the mobile phone includes an image sensor changing an
outside light to an image and a lens opposite to the image
sensor.
The conventional super-small digital camera is fixedly mounted with
the lens and the image sensor to have a trouble in obtaining a high
quality image due to difficulty in adjusting a distance between the
image sensor and the lens.
Recently, a lens driving device such as a voice coil motor has been
developed to adjust a distance between a lens and an image sensor.
The voice coil motor generally includes a bobbin secured with a
lens, a coil block wound on a periphery of the bobbin, a magnet
opposite to the coil block, a yoke securing the magnet, and a leaf
spring elastically supporting the vertically-moving bobbin.
The magnet, one of the essential components of the conventional
voice coil motor, is secured to an inner lateral surface of the
yoke using an adhesive. However, in a case the magnet is secured to
the inner lateral surface of the yoke using an adhesive, the magnet
is separated from the yoke by a strong shock or a vibration applied
to the yoke, and if the magnet is separated from the yoke, the
bobbin is generated with a problem of defective driving.
Another problem encountered by the conventional voice coil motor is
that a yoke is needed to secure a yoke the magnet opposite to the
bobbin whereby the number of parts and assembly processes is
increased.
Still another problem is that an aperture of the lens mounted on
the bobbin cannot be increased due to an area occupied by the
bobbin and the magnet.
BRIEF SUMMARY
The present disclosure is directed to cope with the abovementioned
problems and to provide a VCM (voice coil motor) configured to
inhibit movement of a magnet inside a yoke by outside shock and
vibration.
Technical problems to be solved by the present disclosure are not
restricted to the above-mentioned description, and any other
technical problems not mentioned so far will be clearly appreciated
from the following description by the skilled in the art.
In one general aspect of the present disclosure, there is provided
a VCM, (voice coil motor) comprising: a rotor including a
lens-accommodating, both ends opened cylindrical bobbin and a coil
block including a coil wound on a periphery of the bobbin; a stator
including a cylindrical yoke formed with a lens-exposing opening, a
plurality of magnets disposed inside the yoke and opposite to the
coil block, and a housing disposed inside the yoke to fix the
plurality of magnets; and an elastic member elastically supporting
the bobbin.
In another general aspect of the present disclosure, there is
provided a VCM (voice coil motor), comprising: a rotor including a
lens-accommodating, both ends opened cylindrical bobbin and a coil
block including a coil wound on a periphery of the bobbin; a stator
including a plurality of flat magnets opposite to the coil block
and a yoke formed with pocket units fixing both lateral surfaces of
each flat magnet and a rear surface opposite to a front surface
opposite to the coil block; and elastic member elastically
supporting the bobbin.
In still another general aspect of the present disclosure, there is
provided a VCM (voice coil motor), comprising: a rotor including a
bobbin having a hollow hole mounted with a lens and a coil block
arranged at a periphery of the bobbin; an elastic member
elastically coupled to the bobbin; and a stator including an upper
plate exposing the hollow hole, a housing including a lateral plate
extended from an edge of the upper plate to encompass the rotor and
formed with an accommodation hole, and a flat magnet secured to the
accommodation hole, wherein the housing includes a disengagement
prevention unit preventing the flat magnet from being disengaged
from the lateral plate to a direction facing the coil block.
In still another general aspect of the present disclosure, there is
provided a VCM (voice coil motor) comprising: a rotor including a
lens-mounted bobbin and a coil block arranged at a periphery of the
bobbin; a stator including a flat magnet arranged at a periphery of
the coil block and a bottom spacer securing the flat magnet; an
elastic member elastically supporting the bobbin; and a base in
which the rotor, the bottom spacer and the elastic member are
secured.
The VCM according to exemplary embodiments of the present
disclosure has an advantageous effect in that a magnet arranged
inside a yoke is press-fitted using a housing to inhibit a reduced
driving efficiency and a driving imperfection of a rotor generated
by movement of the magnet inside the yoke.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further
understanding of the present disclosure and are incorporated in the
present disclosure and constitute a part of this application, and
together with the description, serve to explain the principle of
the disclosure. In the drawings:
FIG. 1 is an exploded perspective view illustrating a VCM according
to an exemplary embodiment of the present disclosure;
FIG. 2 is an exploded perspective view of a stator in FIG. 1;
FIG. 3 is a coupled perspective view of a stator in FIG. 2;
FIG. 4 is a cross-sectional view of line `I-I'` in FIG. 3;
FIG. 5 is a perspective view illustrating a housing of a stator of
a VCM according to another exemplary embodiment of the present
disclosure;
FIG. 6 is a perspective view illustrating a housing of a stator of
a VCM according to still another exemplary embodiment of the
present disclosure;
FIG. 7 is a cross-sectional view illustrating a stator of a VCM
according to still another exemplary embodiment of the present
disclosure;
FIG. 8 is an exploded perspective view illustrating a VCM according
to an exemplary embodiment of the present disclosure;
FIG. 9 is an exploded perspective view of magnet and bobbin of
stator of FIG. 8;
FIG. 10 is a plan view of FIG. 9;
FIG. 11 is a plan view of a yoke and a magnet of VCM according to
another exemplary embodiment of the present disclosure;
FIG. 12 is an exploded perspective view of a VCM according to an
exemplary embodiment of the present disclosure;
FIG. 13 is an assembled cross-sectional view of FIG. 12;
FIG. 14 is a cross-sectional view cut along line I-I' of FIG.
12;
FIG. 15, FIG. 16, and FIG. 17 illustrates front views of lateral
plate of FIG. 14;
FIG. 18 is a cross-sectional view of a disengagement prevention
unit of a housing according to an exemplary embodiment of the
present disclosure;
FIG. 19 a cross-sectional view of a disengagement prevention unit
of a housing according to another exemplary embodiment of the
present disclosure;
FIG. 20 is an exploded perspective view of a VCM according to an
exemplary embodiment of the present disclosure;
FIG. 21 is an exploded perspective view of a flat magnet and a
bottom spacer in FIG. 20;
FIG. 22 is an assembled perspective view of a flat magnet and a
bottom spacer in FIG. 21; and
FIG. 23 is a front view of a flat magnet coupled to the bottom
spacer of FIG. 22.
DETAILED DESCRIPTION
Advantages and features of the present invention may be understood
more readily by reference to the following detailed description of
exemplary embodiments and the accompanying drawings. Detailed
descriptions of well-known functions, configurations or
constructions are omitted for brevity and clarity so as not to
obscure the description of the present disclosure with unnecessary
detail. Thus, the present disclosure is not limited to the
exemplary embodiments which will be described below, but may be
implemented in other forms. In the drawings, the width, length,
thickness, etc. of components may be exaggerated or reduced for the
sake of convenience. Furthermore, throughout the descriptions, the
same reference numerals will be assigned to the same elements in
the explanations of the figures, and explanations that duplicate
one another will be omitted. Accordingly, the meaning of specific
terms or words used in the specification and claims should not be
limited to the literal or commonly employed sense, but should be
construed or may be different in accordance with the intention of a
user or an operator and customary usages. Therefore, the definition
of the specific terms or words should be based on the contents
across the specification.
The terms "first," "second," and the like, herein do not denote any
order, quantity, or importance, but rather are used to distinguish
one element from another, and the terms "a" and "an" herein do not
denote a limitation of quantity, but rather denote the presence of
at least one of the referenced item.
As may be used herein, the terms "substantially" and
"approximately" provide an industry-accepted tolerance for its
corresponding term and/or relativity between items. Such an
industry-accepted tolerance ranges from less than one percent to
ten percent and corresponds to, but is not limited to, component
values, angles, et cetera. Such relativity between items ranges
from less than one percent to ten percent.
FIG. 1 is an exploded perspective view illustrating a VCM according
to an exemplary embodiment of the present disclosure, FIG. 2 is an
exploded perspective view of a stator in FIG. 1, FIG. 3 is a
coupled perspective view of a stator in FIG. 2, and FIG. 4 is a
cross-sectional view of line `I-I'` in FIG. 3.
Referring to FIG. 1, a VCM (800) includes a rotor (100), an elastic
member (200) and a stator (300). The VCM (800) may further include
a case (400), a cover can (600) and a spacer (700).
The rotor (100) includes a bobbin (150) and a coil block (190). The
bobbin (150) takes the shape of both ends-opened barrel. The bobbin
may take the shape of both ends-opened cylinder, for example. The
bobbin serves to secure a lens opposite to an image sensor changing
an outside light to an image.
An inner surface of the bobbin (150) is formed with a female screw
unit (112) for accommodating the lens to the bobbin, and the female
screw unit (112) may be formed with a lens fixing member (not
shown) coupled to the lens.
Alternatively, it should be also appreciated that the lens is
directly coupled to the female screw unit of the bobbin (150). A
peripheral bottom distal end of the bobbin (150) is formed with a
hitching sill (118) for supporting a coil block (190, described
later).
The coil block (190) is arranged at a periphery of the bobbin
(150), and secured by using the hitching sill (118) formed at the
peripheral bottom of the bobbin (150).
The coil block (190) may be formed by winding a coil on the
periphery of the bobbin (150) in the shape of a cylinder, or by
inserting a cylindrically wound coil block (190) to the periphery
of the bobbin (150). In a case the coil block (190) is formed by
inserting a cylindrically wound coil block (190) to the periphery
of the bobbin (150), an adhesive may be interposed between the coil
block (190) and the bobbin (150).
The coil block (190) is electrically connected to first elastic
members (210) of elastic member (200, described later), and a
magnetic field is generated from the coil block (190) by a driving
signal provided from the first elastic members (210). The rotor
(100) is driven relative to a magnet (350) by a force generated by
a magnetic field of the coil block (190) and a magnetic field of
the magnet (350, described later).
In the exemplary embodiment of the present disclosure, a gap
between a lens mounted on the bobbin (150) and an image sensor (not
shown) opposite to the lens can be accurately adjusted by adjusting
a level of a driving signal applied to the coil block (190).
The elastic member (200) includes a first elastic member (210) and
a second elastic member (220). In the exemplary embodiment of the
present disclosure, each of the first elastic member (210) and the
second elastic member (220) may include a leaf spring.
The first elastic member (210) and the second elastic member (220)
according to the exemplary embodiment of the present disclosure
serve to elastically support the bobbin (150), inhibit the bobbin
(150) from being disengaged from a predetermined position, and
return the bobbin (150) lifted by the coil block (190) and the
magnet (350) to an initial position.
The first elastic member (210) is coupled to a bottom surface (117)
of the bobbin (150). The first elastic member (210) is coupled to a
boss (not shown) protruded from the bottom surface (117) of the
bobbin (150). The first elastic member (210) includes a through
hole coupled to the boss protruded from the bottom surface (117) of
the bobbin (150). A distal end of the boss is applied with heat and
pressure after the first elastic member (210) is inserted into the
boss protruded from the bottom surface (117) of the bobbin (150).
An upper surface of the first elastic member (210) is secured to
the boss by the distal end of the boss fused by the heat and
pressure applied to the boss, whereby the first elastic member
(210) is inhibited from being disengaged from the bottom surface
(117) of the bobbin (150).
The first elastic member (210) may be formed in a pair according to
the exemplary embodiment of the present disclosure, and the pair of
first elastic members (210) is mutually electrically insulated
therebetween, and the electrically insulated pair of first elastic
members (210) includes a connection terminal which is in turn
electrically connected to an outside circuit substrate.
One distal end of the coil forming the coil block (190) and the
other distal end facing the one distal end of the coil are
electrically connected to the pair of first elastic members (210).
As a result, the driving signal provided from the outside circuit
substrate is provided to the coil block (190) through the first
elastic members (210), and a magnetic field is generated from the
coil block (190) by the driving signal.
The second elastic member (220) is coupled to an upper surface
(116) opposite to the bottom surface (117) of the bobbin (150).
Referring to FIGS. 2, 3 and 4, the stator (300) includes a yoke
(310), a magnet (350) and a housing (370) (for example, a magnet
fixing member style housing). The yoke (310) includes an upper
plate (312) and a lateral plate (314). The upper plate (312) and
the lateral plate (314) may include a metal.
The yoke (310) including the metal serves to inhibit a magnetic
flux generated from the magnet (350, described later) from leaking,
and induce the magnetic flux generated from the magnet (350,
described later) to direct to the coil block (190), whereby a
driving efficiency of the rotor (100) can be further enhanced.
An upper plate (312) of the yoke (310) takes the shape of a square
plate, for example, and the yoke (310) is centrally formed with an
opening (311) exposing the lens mounted on the bobbin (150). The
lateral plate (314) of the yoke (310) is extended from each edge of
the upper plate (312) to a direction encompassing the coil block
(190), where the upper plate (312) and the lateral plate (314) of
the yoke (312) are integrally formed.
In the exemplary embodiment of the present disclosure, each of the
magnets (350) takes the shape of a cuboidal plate, for example, and
is arranged at an inner lateral surface of the lateral plate (314)
of the yoke (310). For example, in a case four lateral plates (314)
of the yoke (310) are formed, each of four magnets (350) is
arranged at each of the four lateral plates (314). Each of the
magnets (350) is arranged to face the coil block (190).
In the exemplary embodiment of the present disclosure, the cuboidal
magnets (350) are arranged in parallel with each of the lateral
plates (314), and each of the magnets (350) is arranged adjacent to
the inner lateral surface of the lateral plate (314). The each of
the magnets (350) generates magnetic field, and a force generated
by a magnetic field generated by the each magnet (350) and a
magnetic field generated by the coil block (190) opposite to the
magnets (350) drives the rotor (100).
A housing (370) secures the magnets (350) arranged inside the yoke
(310). In the exemplary embodiment of the present disclosure, the
magnets (350) can be inhibited from being moved or being disengaged
from designated positions by shock or vibration applied from
outside, by being fixed to the housing (370).
The housing (370) includes a body unit (372) and a coupling unit
(374). The body unit (372) is arranged at an inner lateral surface
of the upper plate (312) of the yoke (310), and takes the shape of
an opening-formed frame. The opening of the body unit (372) takes
the shape and size appropriate enough not to expose the lens of the
bobbin (150). The body unit (372) serves as a base for securing the
coupling unit (374) to a predetermined position.
In the exemplary embodiment of the present disclosure, the body
unit (372) takes the shape of a square frame, for example. The body
unit (372) may take various shapes based on arrangement of magnets
(350) disposed inside the yoke (310). For example, in a case four
magnets, each having the shape of a cuboidal plate, are arranged in
a square shape, the body unit (372) takes the shape of a square
frame. Alternatively, in a case a plurality of magnets, each having
a curved plate shape, is arranged in a circle, the body unit (372)
takes the shape of a circular frame.
A plurality of coupling units (374) is protruded from the body unit
(372) along the lateral plate (314) of the yoke (310). Each of the
coupling units (374) is formed at a position corresponding to a
pair of magnets (350) adjacent to the magnets (350) arranged along
the lateral plates (314) of yoke (310). The coupling units (374)
and the magnets (350) are mutually coupled by press-fitting
method.
In the exemplary embodiment of the present disclosure, each of the
coupling units (374) protruded from the body unit (372) is
protruded in the shape of a rectangular pillar, and the magnets
(350) arranged in parallel with the lateral plates (314) of the
yoke (310) and the rectangular pillar-shaped coupling units (374)
are mutually formed at an obtuse angle.
To be more specific, the angle formed by the coupling unit (374)
and the magnets (350) may be 135.degree., for example. Both lateral
walls of the coupling unit (374) opposite to each distal end of the
adjacent pair of magnets (350) are formed with coupling grooves
(375) for being coupled with distal ends of the magnets (350).
In the exemplary embodiment of the present disclosure, the magnet
(350) is coupled to the coupling unit (374) by allowing the magnets
(350) to be press-fitted into the coupling grooves (375) to a
direction facing a bottom surface of the coupling unit (374) from
an upper surface of the coupling unit (374).
In the exemplary embodiment of the present disclosure, the
press-fitting method may be categorized into three types based on
dimensional relationship of the coupling grooves (375) and the
magnets (350), that is, a forced press-fitting method where there
is no gap between the coupling groove (375) and the magnet (350), a
middle press-fitting method where there is a gap or no gap between
the coupling groove (375) and the magnet (350), and a loose
press-fitting method where there is always a gap between the
coupling groove (375) and the magnet (350). In the exemplary
embodiment of the present disclosure, all the structural methods
may be included capable of inhibiting vertical or horizontal
movement of the magnet within a predetermined range.
In the exemplary embodiment of the present disclosure, as the
magnets (350) are coupled to the coupling groove (375) to a
direction from the upper surface of the coupling unit (374) to a
bottom surface of the coupling unit (374), the magnets (350) can be
secured to a predetermined position without moving to a direction
facing the coil block (19) even if there is a strong shock or
vibration from outside.
In the exemplary embodiment of the present disclosure, the body
unit (372) and the coupling unit (374) of the housing (370) fixing
the magnet (350) include a synthetic resin capable of injection
molding, where the body unit (372) and the coupling unit (374) are
integrally formed by the injection molding.
Although the exemplary embodiment of the present disclosure has
explained that the housing (370) can be formed by the injection
molding of synthetic resin, the housing (370) can be alternatively
formed by press work of a light metal.
Although the magnet (350) secured to the housing (370) has a
structure of easily being disengaged to the upper surface of the
coupling unit (374), the magnet (350) secured to the housing (370)
is brought into contact with the spacer (700) of FIG. 1, and the
spacer (700) inhibits the magnet (350) from being disengaged from
the housing (370), whereby the magnet (350) becomes vertically
fixed.
Meanwhile, the housing (370) may be simply contacted to the inner
lateral surface of the upper plate (312) of yoke (310), an adhesive
(378) may be arranged between the housing (370) and the inner
lateral surface of the upper plate (312) of yoke (310) in order to
inhibit the housing (370) from moving inside the yoke (310).
Alternatively, it should be apparent that a concave groove for
inserting the body unit (372) may be formed at the upper plate
(312) contacted by the body unit (372) of the housing (370) in
order to securing the housing (370) to the upper plate (312) of the
yoke (310).
FIG. 5 is a perspective view illustrating a housing of a stator of
a VCM according to another exemplary embodiment of the present
disclosure.
The VCM illustrated in FIG. 5 has the substantially same structure
as that of FIGS. 1 to 4 except for the coupling unit of the
housing, such that like reference numerals refer to like elements
throughout, and explanations that duplicate one another will be
omitted.
Referring to FIG. 5, the housing (370) includes a body unit (372)
and a coupling unit (374a). The coupling unit (374a) is protruded
from the body unit (372) along the lateral plate (314) of the yoke
(310) and takes the shape of a triangular pillar. Two lateral
surfaces of the coupling unit (374a) having the triangular pillar
shape are arranged parallel with an adjacent pair of lateral plates
(314) and formed with coupling grooves (375a) to be coupled to the
magnets (350) in the press-fitting method.
FIG. 6 is a perspective view illustrating a housing of a stator of
a VCM according to still another exemplary embodiment of the
present disclosure.
The VCM illustrated in FIG. 6 has the substantially same structure
as that of FIGS. 1 to 4 except for the coupling unit of the
housing, such that like reference numerals refer to like elements
throughout, and explanations that duplicate one another will be
omitted.
Referring to FIG. 6, the housing (370) includes a body unit (372)
and a coupling unit (374b). The coupling unit (374b) is protruded
from the body unit (372) along the lateral plate (314) of the yoke
(310) and takes the shape of a circular cylinder. A periphery of
the coupling unit (374b) having the circular cylinder shape is
arranged with a coupling groove (375b) to be coupled to the magnets
(350) in the press-fitting method.
FIG. 7 is a cross-sectional view illustrating a stator of a VCM
according to still another exemplary embodiment of the present
disclosure.
The VCM illustrated in FIG. 7 has the substantially same structure
as that of FIGS. 1 to 4 except for the coupling unit of the
housing, such that like reference numerals refer to like elements
throughout, and explanations that duplicate one another will be
omitted.
Referring to FIG. 7, the housing (370) includes a body unit (372)
and a magnet insertion groove (372a).
In the exemplary embodiment of the present disclosure, the body
unit (372) takes the shape of a square frame that is brought into
contact with an inner lateral surface of the upper plate (312) of
yoke (310), and is formed at an upper surface opposite to the inner
lateral surface of the upper plate (312) of yoke (310) with the
magnet insertion groove (372a) adequate enough to accommodate the
magnet (350). Depth of the magnet insertion groove (372a) is
preferably formed with a depth deep enough to inhibit the magnet
(350) from being disengaged from the body unit (372).
In the exemplary embodiment of the present disclosure, the body
unit (372) is formed with the magnet insertion groove (372a) into
which the magnet (350) is inserted, whereby the magnet (350) can be
securely fixed to the body unit (372) without forming a coupling
unit that is coupled to the magnet (350).
Although the exemplary embodiment of the present disclosure has
illustrated and explained that the magnet (350) is coupled via
press-fitting method to the injection-molded frame in the yoke
(310), it should be apparent that a part of the upper plate of the
yoke is cut out and bent to form a housing for securing the magnet
(350) to the upper plate (312) of the yoke and the housing is
coupled to the magnet (350).
Referring to FIG. 1 again, the case (400) includes an upper case
(410) and a bottom case (420). The case (400) serves to mutually
couple and fix the rotor (100), the elastic member (200) and the
stator (300). The upper case (410) includes an upper plate (411)
and a coupling pillar (412). The upper case (310) is arranged on an
upper surface of the yoke (310), and the second elastic member
(220) in the elastic member (200) is interposed between the upper
case (410) and the yoke (310).
The upper plate (411) of the upper case (310) takes the shape of a
square plate when viewed from a top plan view, and is centrally
formed with an opening (414) for exposing the bobbin (150).
The coupling pillar (412) of the upper case (410) is protruded in
parallel with the bobbin (150) from the four corners of the upper
plate (411), and is coupled to the bottom case (420, described
later). The bottom case (420) includes pillars (424) coupled to
each coupling pillar (412) of the upper case (410).
As noted from the foregoing, there is an advantageous effect in
that the driving efficiency reduction and driving imperfection of
the rotor generated by movement of magnet inside the yoke can be
inhibited by coupling the magnet arranged inside the yoke using the
housing via press-fitting method.
Now, another exemplary embodiment of the present disclosure will be
described with reference to the accompanying drawings.
In the drawings, the width, length, thickness, etc. of components
may be exaggerated or reduced for the sake of convenience.
Furthermore, throughout the descriptions, the same reference
numerals will be assigned to the same elements in the explanations
of the figures, and explanations that duplicate one another will be
omitted. Accordingly, the meaning of specific terms or words used
in the specification and claims should not be limited to the
literal or commonly employed sense, but should be construed or may
be different in accordance with the intention of a user or an
operator and customary usages. Therefore, the definition of the
specific terms or words should be based on the contents across the
specification.
FIG. 8 is an exploded perspective view illustrating a VCM according
to an exemplary embodiment of the present disclosure, FIG. 9 is an
exploded perspective view of magnet and bobbin of stator of FIG. 8,
and FIG. 10 is a plan view of FIG. 9.
Referring to FIG. 8, a VCM (800) includes a rotor (100), an elastic
member (200) and a stator (300). The VCM (800) may further include
an upper spacer (400), a cover can (600) and a base (420).
The rotor (100) includes a bobbin (150) and a coil block (190). The
bobbin (150) takes the shape of both ends-opened barrel. The bobbin
may take the shape of both ends-opened cylinder, for example. The
bobbin serves to secure a lens opposite to an image sensor changing
an outside light to an image.
An inner surface of the bobbin (150) is formed with a female screw
unit (112) for accommodating the lens to the bobbin (150), and the
female screw unit (112) may be formed with a lens fixing member
(not shown) coupled to the lens.
Alternatively, it should be also appreciated that the lens is
directly coupled to the female screw unit of the bobbin (150). A
peripheral bottom distal end of the bobbin (150) is formed with a
hitching sill (115) for supporting a coil block (190, described
later).
The coil block (190) is arranged at a periphery of the bobbin
(150), and secured by using the hitching sill (118) formed at the
peripheral bottom of the bobbin (150).
The coil block (190) may be formed by winding a coil on the
periphery of the bobbin (150) in the shape of a cylinder, or by
inserting a cylindrically wound coil block (190) to the periphery
of the bobbin (150). In a case the coil block (190) is formed by
inserting a cylindrically wound coil block (190) to the periphery
of the bobbin (150), an adhesive may be interposed between the coil
block (190) and the bobbin (150).
The coil block (190) is electrically connected to first elastic
members (210) of elastic member (200, described later). The rotor
(100) is driven relative to a magnet (350) by a force generated by
a magnetic field of the coil block (190) and a magnetic field of
the magnet (350, described later).
In the exemplary embodiment of the present disclosure, a gap
between a lens mounted on the bobbin (150) and an image sensor (not
shown) opposite to the lens can be accurately adjusted by adjusting
a level of a driving signal applied to the coil block (190).
The elastic member (200) includes a first elastic member (210) and
a second elastic member (220). In the exemplary embodiment of the
present disclosure, each of the first elastic member (210) and the
second elastic member (220) may include a leaf spring.
The first elastic member (210) and the second elastic member (220)
according to the exemplary embodiment of the present disclosure
serve to elastically support the bobbin (150), inhibit the bobbin
(150) from being disengaged from a predetermined position, and
return the bobbin (150) lifted by the coil block (190) and the
magnet (350) to an initial position.
The first elastic member (210) is coupled to a bottom surface (117)
of the bobbin (150). The first elastic member (210) is coupled to a
boss (not shown) protruded from the bottom surface (117) of the
bobbin (150). The first elastic member (210) includes a through
hole coupled to the boss protruded from the bottom surface (117) of
the bobbin (150).
A distal end of the boss is applied with heat and pressure after
the first elastic member (210) is inserted into the boss protruded
from the bottom surface (117) of the bobbin (150). An upper surface
of the first elastic member (210) is secured to the boss by the
distal end of the boss fused by the heat and pressure applied to
the boss, whereby the first elastic member (210) is inhibited from
being disengaged from the bottom surface (117) of the bobbin
(150).
The first elastic member (210) may be formed in a pair according to
the exemplary embodiment of the present disclosure, and the pair of
first elastic members (210) is mutually electrically insulated
therebetween, and the electrically insulated pair of first elastic
members (210) includes a connection terminal which is in turn
electrically connected to an outside circuit substrate.
One distal end of the coil forming the coil block (190) and the
other distal end facing the one distal end of the coil are
electrically connected to the pair of first elastic members (210).
As a result, the driving signal provided from the outside circuit
substrate is provided to the coil block (190) through the first
elastic members (210), and a magnetic field is generated from the
coil block (190) by the driving signal.
The second elastic member (220) is coupled to an upper surface
(116) opposite to the bottom surface (117) of the bobbin (150).
Referring to FIGS. 9 and 10, the stator (300) includes a yoke (310)
and a magnet (350). In the exemplary embodiment of the present
disclosure, the magnet (350) includes four magnets, for example.
Hereinafter, the four magnets (350) are defined as a first magnet
(352), a second magnet (354), a third magnet (356) and a fourth
magnet (358).
The first, second, third and fourth magnets (352, 354, 356, 358)
are arranged about the coil block (190), where the first magnet
(352) is arranged opposite to the third magnet (356), and the
second magnet (354) is arranged opposite to the fourth magnet
(358). The first, second, third and fourth magnets (352, 354, 356,
358) are mutually and vertically arranged.
In the exemplary embodiment of the present disclosure, each of the
first, second, third and fourth magnets (352, 354, 356, 358)
includes an inner lateral surface (350a) facing the coil block
(190), an outer lateral surface (350b) opposite to the inner
lateral surface (350a), and a lateral surface (350c) connecting the
inner and outer lateral surfaces (350a, 350b).
The yoke (310) includes lateral plates (311, 312, 313, 314), and
the number of the lateral plates (311, 312, 313, 314) is formed
corresponding to that of the magnet (350). The yoke (310) includes
a metal material and improves a driving efficiency of the rotor
(100) by inhibiting the magnetic flux generated by the magnet (350,
described later) from leaking and by inducing the magnetic flux
generated by the magnet (350) to face the coil block (190).
In the exemplary embodiment of the present disclosure, the yoke
(310) is also formed with four lateral plates (311, 312, 313, 314),
because the coil block (190) is arranged thereabout with the first,
second, third and fourth magnets (352, 354, 356, 358).
In the exemplary embodiment of the present disclosure, the yoke
(310) may take the shape of a square frame when viewed in a top
plane view.
Hereinafter, the four lateral plates (311, 312, 313, 314) of the
yoke (310) are respectively defined as a first lateral plate (311),
a second lateral plate (312), a third lateral plate (313) and a
fourth lateral plate (314).
The first lateral plate (311) is arranged at a position
corresponding to the first magnet (352), the second lateral plate
(312) is arranged at a position corresponding to the second magnet
(354), the third lateral plate (313) is arranged at a position
corresponding to the third magnet (356) and the fourth lateral
plate (314) is arranged at a position corresponding to the fourth
magnet (358).
An external surface (350b) of the first magnet (352) is arranged
opposite to an inner lateral surface of the first lateral plate
(311), an external surface (350b) of the second magnet (354) is
arranged opposite to an inner lateral surface of the second lateral
plate (312), an external surface (350b) of the third magnet (356)
is arranged opposite to an inner lateral surface of the third
lateral plate (313) and an external surface (350b) of the fourth
magnet (358) is arranged opposite to an inner lateral surface of
the fourth lateral plate (314).
The first lateral plate (311) is formed with a first pocket unit
(311a) in order to secure the first magnet (352) to a predetermined
position of the first lateral plate (311). The first pocket unit
(311a) fixes the external surface (350b) and lateral surfaces
(350c) of the first magnet (352). The first pocket unit (311a) is
formed by protruding a part of the first lateral plate (311) from
an inner lateral surface toward the external surface, where the
first magnet (352) is inserted into the first pocket unit (311a).
For example, the first magnet (352) may be press-fitted into the
first pocket unit (311a). Alternatively, an adhesive may be
interposed between the first magnet (352) and the first pocket unit
(311a) in order to securely fix the first magnet (352) to the first
pocket unit (311a).
In the exemplary embodiment of the present disclosure, the
press-fitting method may be categorized into three types based on
dimensional relationship of the first, second, third and fourth
magnets (352, 354, 356, 358) and first, second, third and fourth
pocket units (311a, 312a, 313a, 314a), that is, a forced
press-fitting method where there is no gap, a middle press-fitting
method where there is a gap or no gap, and a loose press-fitting
method where there is always a gap. In the exemplary embodiment of
the present disclosure, all the structural methods may be included
capable of inhibiting vertical or horizontal movement of the first,
second, third and fourth magnets (352, 354, 356, 358) within a
predetermined range.
The second pocket unit (312a) is formed at the second lateral plate
(312) in order to fix the second magnet (354) to a predetermined
position of the second lateral plate (312). The second pocket unit
(312a) fixes the external surface (350b) and lateral surface (350c)
of the second magnet (354). The second pocket unit (312a) is formed
by protruding a part of the second lateral plate (312) from an
inner lateral surface to the external surface. For example, the
second magnet (354) may be press-fitted into second pocket unit
(312a). Alternatively, an adhesive may be interposed between the
second magnet (354) and the second pocket unit (312a) in order to
securely fix the second magnet (354) to the second pocket unit
(312a).
The third pocket unit (313a) is formed at the third lateral plate
(313) in order to fix the third magnet (356) to a predetermined
position of the third lateral plate (313). The third pocket unit
(313a) fixes the external surface (350b) and lateral surface (350c)
of the third magnet (356). The third pocket unit (313a) is formed
by protruding a part of the third lateral plate (313) from an inner
lateral surface to the external surface. For example, the third
magnet (356) may be press-fitted into third pocket unit (313a).
Alternatively, an adhesive may be interposed between the third
magnet (356) and the third pocket unit (313a) in order to securely
fix the third magnet (356) to the third pocket unit (313a).
The fourth pocket unit (314a) is formed at the fourth lateral plate
(314) in order to fix the fourth magnet (358) to a predetermined
position of the fourth lateral plate (314). The fourth pocket unit
(314a) fixes the external surface (350b) and lateral surface (350c)
of the fourth magnet (358). The fourth pocket unit (314a) is formed
by protruding a part of the fourth lateral plate (314) from an
inner lateral surface to the external surface. For example, the
fourth magnet (358) may be press-fitted into fourth pocket unit
(314a). Alternatively, an adhesive may be interposed between the
fourth magnet (358) and the fourth pocket unit (314a) in order to
securely fix the fourth magnet (358) to the fourth pocket unit
(314a).
In the exemplary embodiment of the present disclosure, the magnet
(350) can be inhibited from being disengaged from the yoke (310) by
external shock or vibration by arranging the first, second, third
and fourth pocket units (311a, 312a, 313a, 314a) on the first,
second, third and four lateral plates (311, 312, 313, 314) of the
yoke (310).
Furthermore, because positions of the first, second, third and
fourth magnets (352, 354, 356, 358) are determined by the first,
second, third and fourth pocket units (311a, 312a, 313a, 314a)
formed at the first, second, third and fourth lateral plates (311,
312, 313, 314), the positions of the first, second, third and
fourth magnets (352, 354, 356, 358) are inhibited from being
changed or being arranged at positioned deviated from designated
positions.
A magnet support unit (316) may be formed by extending or bending a
bottom end of the first, second, third and fourth lateral plates
(311, 312, 313, 314) toward the bottom surface of the first,
second, third and fourth magnets (352, 354, 356, 358).
Meanwhile, in order for the first, second, third and fourth magnets
(352, 354, 356, 358) from being disengaged from an upper surface
opposite to the bottom surface of the first, second, third and
fourth pocket units (311a, 312a, 313a, 314a), the yoke (310) may
include an additional magnet support unit extended from the first,
second, third and fourth pocket units (311a, 312a, 313a, 314a) to
the upper surface of the first, second, third and fourth magnets
(352, 354, 356, 358).
Meantime, referring to FIGS. 9 and 10, the yoke (310) included in
the stator (300) may include a curvature yoke plate (370) arranged
in parallel with the coil block (190) from a portion corresponding
to the magnets (350) to inhibit the magnetic field generated by the
coil block (190) from leaking.
Each magnet (350) fixed by the yoke (310) generates a magnetic
field, and the rotor (100) is driven by a repulsive force generated
by the magnetic field generated by the magnets (350) and the
magnetic field generated by the coil block (19) facing the magnets
(350).
Referring to FIG. 8 again, the upper spacer (400) includes an upper
plate (411) and a coupling pillar (412). The upper spacer (400) is
arranged on the magnet support unit (316), and the second elastic
member (220) of the second elastic member (200) is interposed
between the upper spacer (400) and the yoke (310).
The upper plate (411) of the upper spacer (400) takes the shape of
a square plate when viewed in a top plane view, and is centrally
formed with an opening (414) for exposing the bobbin (150). The
coupling pillar (412) of the upper spacer (400) is protruded in
parallel with the bobbin (150) from four corners of the upper plate
(411), and the coupling pillar (412) is coupled to the base (420,
described later). The base (420) includes pillars (425) coupled to
the each coupling pillar (412) of upper spacer (400).
FIG. 11 is a plan view of a yoke and a magnet of VCM according to
another exemplary embodiment of the present disclosure.
The VCM illustrated in FIG. 11 has the substantially same structure
as that of FIGS. 8 to 10 except for the yoke, such that like
reference numerals refer to like elements throughout, and
explanations that duplicate one another will be omitted.
Referring to FIG. 11, the yoke (310) takes the shape of an
pentagonal frame, and mutually facing four lateral plates among
eight lateral surfaces of the yoke (310) are respectively defined
as first, second, third and fourth pocket units (311a, 312a, 313a,
314a), and the first, second, third and fourth pocket units (311a,
312a, 313a, 314a) are fixed with the first, second, third and
fourth magnets (352, 354, 356, 358).
As apparent from foregoing, there is an advantageous effect in that
a magnet can be inhibited from moving inside a yoke by forming a
pocket unit at the yoke and fixing the magnet at the pocket unit,
the magnet can be inhibited from being disengaged from the yoke by
outside shock, the magnet can be secured at a predetermined
position and the magnet can be arranged inside the yoke by
automatic facility
FIG. 12 is an exploded perspective view of a VCM according to an
exemplary embodiment of the present disclosure, and FIG. 13 is an
assembled cross-sectional view of FIG. 12.
Referring to FIGS. 12 and 13, a VCM (800) includes a rotor (100),
elastic members (300, 400) and a stator (600). The VCM (800) may
further include a base (100) and a cover can (700).
The rotor (100) includes a bobbin (210) and a coil block (250). The
bobbin (210) takes the shape of a hollow hole-formed cylinder and
is mounted therein with a lens (not shown). The bobbin is
alternatively formed at a periphery with a curvature unit (214) and
a planar unit (216). In the exemplary embodiment of the present
disclosure, four curvature units (214) and planar units (216) are
respectively alternatively formed.
The curvature unit (214) formed at the periphery of the bobbin
(210) is formed with a bond tank (215) for fixing a coil block
(250, described later), and the bond tank (215) takes the shape of
a recess concaved from the curvature unit (214).
Although the exemplary embodiment of the present disclosure
illustrated and explained the bond tank (215) formed at the
curvature unit (214), it should be apparent that the bond tank
(215) may be formed at the planar unit (216).
Meantime, part of an upper end of each curvature unit (214) formed
at the periphery of the bobbin (210) is cut out to allow the
curvature unit (214) of the bobbin (210) to be formed with a
stair-cased hitching sill (214a), and the bond tank (215) is linked
to the hitching sill (214a).
A support unit (218) is formed at a bottom end of the periphery of
the bobbin (210) for supporting the coil block (250, described
later), and is protruded along the peripheral bottom end of the
bobbin (210) in the shape of a rib. The support unit (218) may
include a partially cut-out unit (219) through which both ends of
the coil block (250, described later) can pass.
The coil block (250) included in the rotor (200) takes the shape of
a cylinder, and is formed by winding an insulation resin-coated
wire such as enamel resin in the shape of a cylinder. The coil
block (250) may be directly wound on the periphery of the bobbin
(210). The coil block (250) formed on the periphery of bobbin (210)
is bonded to the bobbin (210) via an adhesive provided to the bond
tank (215). Both ends (252, 254) of the coil block (250) arranged
on the periphery of the bobbin (210) are protruded to a bottom
surface of the bobbin (210) through the cut-out unit (219) of the
support unit (218) formed at the bobbin (210).
The both ends (252, 254) of the coil block (250) protruded to the
bottom surface of the bobbin (210) through the cut-out unit (219)
of the support unit (218) formed at the bobbin (210) are
electrically connected to a first elastic member (300) among the
elastic members (300, 400, described later). The elastic members
(300, 400) include a first elastic member (300) and a second
elastic member (400).
The first elastic member (300) is coupled to the bottom surface of
the bobbin (210), and the second elastic member (400) is arranged
on an upper surface of the bobbin (210). A pair of first elastic
members (300) is arranged on the bottom surface of the bobbin
(210), and the pair of first elastic members (300) serves to
support the bottom surface of the bobbin (210). Each of the pair of
first elastic members (300) arranged at the bottom surface of the
bobbin (210) is electrically isolated from the other, such that
each of the pair of first elastic members (300) is not mutually
contacted.
Each of the pair of first elastic members (300) coupled to the
bottom surface of bobbin (210) may be formed by etching process or
press work of a conductive metal plate. Each of the pair of first
elastic members (300) is symmetrically formed about the bobbin
(210). Each of the pair of first elastic members (300) includes an
inner elastic unit (302), an external elastic unit (304) and a
connection elastic unit (306).
Each inner elastic unit (302) takes the shape of a semi-circular
plate when viewed in a top plane view, and is formed with a through
hole (303) coupled to a boss (213) formed at the bottom surface of
the bobbin (210). Each inner elastic unit (302) is fixed at the
bottom surface of the bobbin (210).
Each inner elastic unit (302) is electrically connected to both
ends (252, 254) of the coil block (250). For example, each inner
elastic unit (302) is electrically connected to both ends (252,
254) of the coil block (250) via a solder.
Each of the external elastic units (304) is arranged at a periphery
of the inner elastic unit (302) and takes the shape of a
semi-circular plate when viewed in a top plan view. Each of the
external elastic units (304) is formed with a through hole (305)
coupled to the boss (130) formed at an upper surface (110) of the
base (100, described later).
Each of the connection elastic units (306) serves to elastically
connect the inner elastic unit (302) and the external elastic units
(304), and may take the shape of a zigzag when viewed in a top plan
view in order to generate elastic force.
In the exemplary embodiment of the present disclosure, the first
elastic member (300) is formed with a terminal unit (310) to be
electrically connected to an outside circuit substrate. An electric
signal provided to the terminal unit (310) is provided to both ends
(252. 254) of the coil block (250) through the pair of first
elastic members (310), whereby a magnetic field is generated from
the coil block (250).
Meanwhile, an upper surface corresponding to the bottom surface of
the bobbin (210) is such that the second elastic member (400) may
be elastically coupled to the upper surface of the bobbin (210).
The second elastic member (400) is coupled to a stroke lug formed
at a housing of the stator (described later).
FIG. 14 is a cross-sectional view cut along line I-I' of FIG.
12.
Referring to FIGS. 12 and 14, the stator (600) includes a flat
magnet (610) and a housing (690). The flat magnet (610) is arranged
opposite to the coil block (250) wound on the bobbin (210), and
includes a plurality of magnets.
In the exemplary embodiment of the present disclosure, each of the
flat magnets (610) takes the shape of a plate, and four flat
magnets (610) are mutually vertically arranged. Each of the flat
magnets (610) takes the shape of a cuboidal plate formed with
mutually facing long sides (612) and mutually facing short sides
(614).
The flat magnet (610) may include a single flat magnet formed with
an N pole and an S pole, or a stacked flat magnet in which at least
two single magnets each stacked with an N pole and an S pole are
stacked. Alternatively, the flat magnet (610) may include a
four-pole flat magnet formed with N pole-S pole-N pole-S pole.
In the exemplary embodiment of the present disclosure, a surface of
the flat magnet (610) opposite to the coil block (250) is defined
as a front surface (601), and a surface opposite to the front
surface (601) of the flat magnet (601) is defined as a rear surface
(602).
The housing (690) functions to secure the flat magnet (610) whereby
the flat magnet (610) faces the coil block (250). In the exemplary
embodiment of the present disclosure, the housing (690) may take
the shape of a bottom surface-opened cuboidal box. The housing
(690) includes a upper plate (620) and a lateral plate (630), and
the flat magnet (610) is fixed at each lateral plate (630).
The upper plate (620) of the housing (690) takes the shape of a
square plate, for example, and is centrally formed with an opening
(621) exposing a lens mounted at the bobbin (210). The lateral
plate (630) of the housing (690) is extended to a direction
encompassing the bobbin (210) from four edges of the upper plate
(620), whereby the housing (690) takes the shape of the bottom
surface-opened cuboidal box.
Meanwhile, a stopper unit (628) is protruded from an inner lateral
surface formed by the opening (621) formed at the upper plate
(620), and the stopper unit (628) is formed at a position
corresponding to each hitching sill (214a) formed at the curvature
unit (214) at the periphery of the bobbin (210). The stopper unit
(628) is brought into contact with the hitching sill (214a) of the
bobbin (210) to restrict a stroke length of the bobbin (210).
In the exemplary embodiment of the present disclosure, the stopper
unit (628) may be formed with a curved surface having a similar or
same curvature as that of the periphery of the bobbin (210), when
viewed in a top plan view.
Stroke lugs (640) are protruded from the upper plate (620) of the
housing (690). Each of the stroke lugs (640) is formed at each
diagonal corner of upper plate (620), and may be formed at each
corner of the upper plate (620). The stroke lugs (640) serve to
secure a stroke space and to fix the second elastic member
(400).
The stroke lug (640) formed at each corner of upper plate (620) is
formed in a pair, and the pair of stroke lugs (640) is
symmetrically formed about the center of the stroke lug (640).
In the exemplary embodiment of the present disclosure, the pair of
stroke lugs (640) may be formed with a shape similar to a
semi-circular pillar. Alternatively, the pair of stroke lugs (640)
may be formed with various shapes including a square pillar and a
polygonal pillar.
Although the exemplary embodiment of the present disclosure
illustrated and explained that the pair of stroke lugs (640) is
symmetrically formed at each corner of upper plate (620) of the
housing (690), alternatively, it should be apparent that the pair
of stroke lugs (640) may be asymmetrically formed at each corner of
upper plate (620) of the housing (690).
Meanwhile, the upper plate (620) of the housing (690) is formed
with a bond tank unit (625) along a circumference of the stroke lug
(640) in the shape of a trench, and the bond tank unit (625) is
provided with an adhesive, and the second elastic member (400) is
bonded to the upper plate (620) of the housing (690) via the
adhesive. A coupling lug (627) is formed at a position adjacent to
the stroke lug (640) of the upper plate (620) at the housing
(690).
The coupling lug (627) is coupled to the housing (690) to a
direction designated by the second elastic member (400), and each
of the diagonally formed coupling lugs (627) formed at the upper
plate (620) of the housing (690) is asymmetrically formed based on
the center of the upper plate (620) in order to inhibit the second
elastic member (400) from being coupled to the housing (690) to a
direction not designated by the second elastic member (400).
A center of each lateral plate (630) of the housing (690) is formed
with a through hole (635) through which each lateral plate (630)
passes, and the flat magnet (610) is coupled to the lateral plate
(630) of the housing (690) using an accommodation hole (635).
FIG. 15 to FIG. 17 illustrates front views of lateral plate of FIG.
14.
Referring to FIGS. 12, 14 and 15, each lateral plate (630) of the
housing (690) includes a disengagement prevention unit (636) to
inhibit the flat magnet (610) accommodated in the accommodation
hole (635) of each lateral plate (630) from being disengaged to a
direction facing the coil block (250).
The disengagement prevention unit (636) inhibits the operation
imperfection of the rotor (200) that is generated by the flat
magnet (610) that is disengaged to a direction facing the coil
block (250) to interfere with the coil block (250).
The disengagement prevention unit (636) is extended from an inner
lateral surface (631) of the lateral plate (630) into the
accommodation hole (635), and is formed with a thickness thin
enough not to interfere with the coil block (250). The
disengagement prevention unit (636) is brought into contact with
both edges of the front surface (601) of the flat magnet (610), for
example. To this end, the disengagement prevention unit (636) is
protruded from the inner lateral surface (631) of the lateral plate
(630) toward both edges of the front surface (601) of the flat
magnet (610).
In the exemplary embodiment of the present disclosure, in a case
the disengagement prevention unit (636) is extended from an inner
lateral surface (631) of the lateral plate (630) into the
accommodation hole (635), the thickness of the flat magnet (610) is
not affected by thickness of the disengagement prevention unit
(636), such that the thickness of the flat magnet (610) can be
formed with the substantially same thickness of the lateral plate
(630). In the exemplary embodiment of the present disclosure, an
external surface of the lateral plate (630) is arranged on the same
planar surface as that of the rear surface (602) of the flat magnet
(610).
As illustrated in FIG. 15, it should be apparent that the
disengagement prevention unit (636) is formed in parallel with the
upper plate (620) of the housing (690), formed in parallel with the
long side (612) of the flat magnet (610) and formed to a second
direction (SD) perpendicular to a first direction (FD).
As illustrated in FIG. 17, it should be apparent that the
disengagement prevention unit (636) is parallel with an axial
direction of the bobbin (250), parallel with the first direction
(FD) parallel with the short side (614) of the flat magnet (610)
and the upper plate (620) of the housing (690), and parallel with
the long side (612) of the flat magnet (610) and the second
direction (SD) perpendicular to the first direction (FD).
FIG. 18 is a cross-sectional view of a disengagement prevention
unit of a housing according to an exemplary embodiment of the
present disclosure.
Referring to FIG. 18, a disengagement prevention unit (637) formed
at the lateral plate (630) of the housing (690) is protruded from
an accommodation surface (635a) formed by the accommodation hole
(635) penetrating each lateral plate (630), and the disengagement
prevention unit (637) is thinner than the lateral plate (630) to
support both edges of the front surface (601) of the flat magnet
(610).
The thickness of each flat magnet (610) is formed with a thickness
minus the thickness of the disengagement prevention unit (637) from
the thickness of the lateral plate (630). Furthermore, in the
exemplary embodiment of the present disclosure, an external surface
of the lateral plate (630) is arranged in the same planar surface
as that of the rear surface (602) of the flat magnet (610).
FIG. 19 a cross-sectional view of a disengagement prevention unit
of a housing according to another exemplary embodiment of the
present disclosure.
Referring to FIG. 19, the disengagement prevention unit (637)
formed at the lateral plate (630) of the housing (690) is protruded
from an accommodation surface (635a) formed by the accommodation
hole (635) penetrating each lateral plate (630), and the
disengagement prevention unit (637) is thinner than the lateral
plate (630).
In a case the disengagement prevention unit (637) formed at the
lateral plate (630) of the housing (690) is protruded from an
accommodation surface (635a) formed by the accommodation hole
(635), the thickness of the flat magnet (610) is affected by the
disengagement prevention unit (637).
In the exemplary embodiment of the present disclosure, in order to
inhibit the thickness of the flat magnet (610) from being reduced
by the disengagement prevention unit (637), the flat magnet (610)
contacting the disengagement prevention unit (637) is formed with
an accommodation groove (613) that accommodates the disengagement
prevention unit (637). The flat magnet (610) can be formed with a
thickness substantially same as that of the lateral plate (630) by
forming the accommodation groove (613) at the flat magnet (610)
regardless of the disengagement prevention unit (637).
Furthermore, in the exemplary embodiment of the present disclosure,
the external surface of the lateral plate (630) is arranged on the
same planar surface as that of the rear surface (602) of the flat
magnet (610). The lateral plate (630) of the housing (690) is
formed with a coupling groove (626) coupled to each coupling pillar
(120) formed at each corner of upper surface (110) of the base
(100, described later).
A socket groove (638) is formed across the accommodation hole (635)
of the pair of lateral plate (630) opposite to the lateral plates
(630) of the housing (690), and the VCM (800) is coupled to the
outside circuit substrate using the socket groove (638).
The cover can (700) includes a cover can upper plate (710) and a
cover can lateral plate (720). In the exemplary embodiment of the
present disclosure, the cover can (700) may be formed by processing
a metal plate capable of blocking a magnetic field or blocking a
hazardous electromagnetic wave.
The cover can upper plate (710) includes an opening corresponding
to the hollow hole of the bobbin (210), and an inner lateral
surface of the cover can upper plate (710) is brought into contact
with an upper surface of each stroke lug (640) protruded from each
corner of the upper plate (620) of the housing (690).
The cover can lateral plate (720) is extended from an edge of the
cover can upper plate (710) to a direction encompassing the lateral
plate (630) of the housing (690), and is brought into contact with
a rear surface (602) of each flat magnet (610) coupled to the
accommodation hole (635) of the lateral plate (630) at the housing
(690).
The flat magnet (610) is prevented from moving backward or forward
from the lateral plate (630) of the housing (690) by the contact
between the rear surface (602) of the flat magnet (610) and the
inner lateral surface of the cover can lateral plate (720).
The cover can lateral plate (720) blocks a magnetic field leaked
from the flat magnet (610) or a hazardous electromagnetic wave. The
rear surface (602) of the flat magnet (610) and the cover can
lateral plate (720) may be mutually adhered by a bond.
In a case the lateral plate (630) of the housing (690) is formed
with the socket groove (638), the cover can lateral plate (720)
encompassing the lateral plate (630) of the housing (690) is formed
with a cut-out unit (725) exposing the socket groove (638).
The base (200) functions to secure the bobbin (210), the first
elastic member (300), the stator (600) and the cover can (700). The
base (100) takes the shape of a cuboidal plate centrally formed
with an opening (105), and is mounted at a rear surface thereof
with an IR (Infrared) filter formed at a front side of an image
sensor module. The IR filter functions to remove the infrared
included in the outside light.
An upper surface (110) opposite to the rear surface of the base
(100) is arranged with a rear surface of the bobbin (210) coupled
to the first elastic member (300). Four corners of the upper
surface (110) of the base (100) are formed four coupling pillars
(120) perpendicularly protruded relative to each upper surface
(110), and each coupling pillar (120) is coupled to the coupling
groove (626) of the housing (690).
The upper surface (110) of the base (100) is formed with bosses
(130) coupled to the first elastic member (300). Furthermore, the
base (100) is formed with through holes (140) through which the
terminal units (310) formed at the first elastic member (300)
pass.
As apparent from the foregoing, the present disclosure has an
advantageous effect in that a flat-shaped flat magnet opposite to a
coil block and generating a magnetic field is formed at an
accommodation hole formed at a lateral plate of a housing, and a
disengagement prevention unit is formed at the lateral plate to
inhibit the flat magnet from being disengaged to enhance the
performance of VCM.
FIG. 20 is an exploded perspective view of a VCM according to an
exemplary embodiment of the present disclosure, FIG. 21 is an
exploded perspective view of a flat magnet and a bottom spacer in
FIG. 20, FIG. 22 is an assembled perspective view of a flat magnet
and a bottom spacer in FIG. 21, and FIG. 23 is a front view of a
flat magnet coupled to the bottom spacer of FIG. 22.
Referring to FIGS. 20 through 23, a VCM (800) includes a rotor
(100), a stator (200), an elastic member (300) and a base (400).
The VCM (800) may further include an upper spacer (500) and a cover
can (600). The rotor (100) includes a bobbin (110) and a coil block
(120).
The rotor (100) includes a lens, and distances the embedded lens
from an image sensor secured to the base (400) to change a gap
between the lens and the image sensor.
The bobbin (110) takes the shape of a hollow hole-formed cylinder,
and is secured therein with a lens. In order to secure the lens to
an inner surface of the bobbin (110), the inner surface of the
bobbin (110) may be formed with a screw thread. A periphery of the
bobbin (110) is formed with four planar units (112), for example,
and each of the four planar units (112) is distanced from the other
at an equal predetermined gap.
Meanwhile, a bottom end of the periphery of the bobbin (110) is
formed with a support unit (114) for supporting the coil block
(120, described later), and the support unit (114) is formed by
protruding from the bottom end of the periphery of the bobbin
(110).
The coil block (120) is formed by winding an insulation resin (such
as enamel resin) coated long wire. The coil block (120) takes the
shape of a barrel arranged at the periphery of the bobbin (110).
The coil block (120) takes the shape of a square barrel with upper
surface and a bottom surface opened.
In a case a current is applied to the coil block (120) wound with a
wire in the shape of a cylinder, a magnetic field is generated from
the coil block (120). The coil block (120) inserted into the
periphery of the bobbin (110) includes four planar surfaces (122)
which are same as the four planar units (112) of the bobbin (110),
and four curvatures (124) connecting the planar surfaces (122).
Referring to FIGS. 21 and 22, the stator (200) includes a flat
magnet (210) and a bottom spacer (250). The flat magnet (210) may
take the shape of a cuboidal plate, for example. A front surface
(212) opposite to the coil block (120) on the flat magnet (210) of
cuboidal shape is arranged opposite to each planar surface (122) of
the coil block (120), whereby the number of flat magnets (210) is
same as that of the planar surface (122) at the coil block
(120).
In the exemplary embodiment of the present disclosure, each of the
four flat magnets (210) is arranged opposite to each of the four
planar surfaces (122), and each of the four flat magnets (210) is
mutually perpendicularly arranged. Each of the flat magnets (210)
may be a two-pole flat magnet or a four-pole flat magnet.
The bottom spacer (250) serves to secure a bottom elastic member
(310) of the elastic member (300, described later) and the flat
magnets (210) as well. The bottom spacer (250) includes a frame
unit (260), a pillar unit (270) and a fixing unit (280) in order to
fix the bottom elastic member (310) and each of the flat magnets
(210).
The frame unit (260) supports each bottom surface of four flat
magnets (210), and takes the shape of a square frame having an
opening when viewed in a top plan view, in order to support the
bottom surface (211) of the four flat magnets (210).
The pillar unit (270) is protruded from an upper surface of the
frame unit (260) opposite to both lateral surfaces (213) of each
flat magnet (210). In the exemplary embodiment of the present
disclosure, each of the pillar unit (270) is protruded from the
upper surface of the frame unit (260) corresponding to the adjacent
pair of flat magnets (210). Each of the pillar units (270) is
protruded from each corner of the upper surface of the frame unit
(260).
Each of the pillar units (270) opposite to both lateral surfaces
(213) of each flat magnet (210) is formed with an inclined guide
unit (275) to allow the flat magnet (210) to be smoothly
inserted.
While the flat magnet (210) is supported to the upper surface of
the frame unit (260), corners (214) formed by a bottom end (276) of
the guide unit (275), a lateral surface (213) and the bottom
surface (211) of the flat magnet (210) meet each other. In a case
the distal end of the guide unit (275) and the corners (214) of the
flat magnet (210) meet, the flat magnet (210) is fixed to a
designated position of the bottom spacer (200).
Meanwhile, as the guide unit (275) is inclined, the flat magnet
(210) can be arranged on the frame unit (260) along the guide unit
(275) formed at each of the pair of pillar units (270) as
illustrated in FIG. 4, in a case the flat magnet (210) is arranged
on the upper surface of the frame unit (260).
Alternatively, in a case the inclined guide unit (275) is not
formed at the pillar unit (270) formed at the frame unit (260), it
is difficult to accurately insert a very small-sized flat magnet
(210) into a very small-sized pillar unit (270) to generate
frequent assembly defects and to take a lot of time in
assembly.
The fixing unit (280) is extended from an inner lateral surface of
each pillar unit (270) formed at the frame unit (260) to a
direction facing the front surface of the flat magnet (210), and
each flat magnet (210) is supported by the fixing unit (280).
The elastic member (300) includes a bottom elastic member (310) and
an upper elastic member (350). Two bottom elastic members (310) are
formed in a pair. The bottom elastic member (310) formed in a pair
is hereinafter defined as a first bottom elastic member (314) and a
second bottom elastic member (319).
The first and second bottom elastic members (314, 319) include
external elastic units (311, 315) formed in the shape corresponding
to that of the frame unit (260) of the bottom spacer (250), inner
lateral elastic units (312, 317) secured to the bottom surface of
the bobbin (110) and connection elastic units (313, 318) connecting
the external elastic units (311, 315) and the inner lateral elastic
units (312, 317). The connection elastic units (313, 318)
elastically support the bobbin (110).
In the exemplary embodiment of the present disclosure, the inner
lateral elastic units (312, 317), the external elastic units (311,
315) and the connection elastic units (313, 318) of the first and
second bottom elastic members (314, 319) are integrally formed.
Meanwhile, the external elastic units (311, 315) of the first and
second bottom elastic members (314, 319) are respectively formed
with terminal units (311a, 315a), and the terminal units (311a,
315a) are bent from the external elastic units (311, 315) to the
bottom. The upper elastic member (350) elastically supports the
bobbin (110) by being coupled to the upper surface of the bobbin
(110).
The upper elastic member (350) includes a square frame-shaped
external elastic unit (352), and an inner lateral elastic unit
(354) coupled to the upper surface of the bobbin (110) and a
connection elastic unit (356) connecting the external elastic unit
(352) and the inner lateral elastic unit (354).
Four corners of the external elastic unit (352) of the upper
elastic member (350) are arranged on an upper surface of each
pillar unit (270) of the bottom spacer (250). The base (400)
secures the rotor (100), the stator (200) and the bottom elastic
member (310) of the elastic member (300). The base (400) takes the
shape of a square plate, and is formed with an opening (410)
corresponding to the hollow hole of the bobbin (110).
An edge of an upper surface (401) of the base (400) is formed with
a lug (403) contacting the external elastic units (311, 315) of the
bottom elastic member (310), and an edge of the upper surface (401)
of the base (400) is formed with a coupling groove (404) coupled to
the coupling lug protruded from the bottom surface of the frame
unit (260) of the bottom spacer (250).
The bottom elastic member (310) is interposed between the frame
unit (260) of the bottom spacer (250) and the lug (403) of the base
(400), and the bottom elastic member (310) is secured by the base
(400) and the frame unit (260) of the bottom spacer (250).
The upper spacer (500) is arranged at an upper surface of the upper
elastic member (350). The upper spacer (500) is formed in a shape
corresponding to the frame unit (260) of the bottom spacer (250)
and is a size corresponding to that of the frame unit (260). A
coupling lug (510) is formed at a position corresponding to the
pillar unit (270) of the bottom spacer (250), and the coupling lug
(510) formed at the upper spacer (500) is coupled to a coupling
hole (275a) formed at the upper surface of the pillar unit (270) of
the bottom spacer (250).
The upper elastic member (350) is coupled to the bottom spacer
(250) and the upper spacer (500) by coupling between the coupling
hole (275a) formed at the pillar unit (270) of the bottom spacer
(250) and the coupling lug (510) of the upper spacer (500).
The cover can (600) includes an upper plate (610) and a lateral
plate (620). The upper plate (610) is formed with an area
substantially the same as that of the base (400), and is centrally
formed with an opening exposing the bobbin (110). The lateral plate
(620) is extended to a direction facing the base (400) from an edge
of the upper plate (610) to be coupled to the base (400).
In inner lateral surface of the lateral plate (620) is brought into
contact with a rear surface of the flat magnet (210) fixed to the
bottom spacer (250), and the lateral plate (620) functions as a
yoke.
As apparent from the foregoing, the VCM according to the exemplary
embodiment of the present disclosure has an advantageous effect in
that a frame unit and a pillar unit protruded from the frame unit
are formed on a bottom spacer, a magnet is arranged at the frame
unit, and the magnet is fixed by protruding a guide unit from the
pillar unit to reduce the number of constituent elements and
assembling processes without using a yoke for fixing the
conventional magnet and to increase an aperture of a bobbin and a
lens mounted at the bobbin. Although embodiments have been
described with reference to a number of illustrative embodiments
thereof, it should be understood that numerous other modifications
and embodiments can be devised by those skilled in the art that
will fall within the spirit and scope of the principles of this
disclosure. More particularly, various variations and modifications
are possible in the component parts and/or arrangements of the
subject combination arrangement within the scope of the disclosure,
the drawings and the appended claims.
* * * * *